1. Field of the Invention
This invention relates to a flapper control valve having a valve port plate and a back plate, each with at least one through hole, which open and close relative to each other to control fluid flow through both plates.
2. Description of the Prior Art
Kirpichenkov, U.S. Pat. No. 4,173,985 teaches a straightway valve having a polyhedral body with outlet ports in seat surfaces on the sides of the polyhedral body. A working cavity is provided within the body of the valve. The cavity within the valve body has a flow splitter or divider which divides the compressed air flow through the body into several streams equal in number to that of the faces of the splitter. Airstreams reflected from the faces of the splitter are driven toward the outlet ports and the flow bends or flexes a closure plate which also bends or flexes a reed-type closing member secured to the closure plate. The '985 patent discloses a straightway valve specifically designed for use as a suction and delivery valve in cylinders for air or gas piston-type compressors.
Villa, U.S. Pat. No. 4,569,208 teaches a pressure relief port which regulates the pressure within an enclosure and a miniature pressure relief port mainly used in regulating pressure within commercial refrigeration enclosures.
Molina, U.S. Pat. No. 4,537,213 teaches a double flapper check valve having a housing divided into two chambers. A valve seat in one chamber angles upward and a valve seat in the opposite chamber angles downward. Gravity holds one flapper valve in the open position and the other flapper valve in a closed position unless the closed flapper valve is opened by a flow of fluid. Rotating the housing of the double flapper check valve 180.degree. will reverse the position of the flapper valve so that the permitted fluid flow will be reversed.
Beling, U.S. Pat. No. 1,121,969 teaches a safety valve having a single conduit leading into a central portion of a tubular section. The tubular section has an air inlet valve on one end and a safety outlet valve on the opposite end. Both valves are spring-biased, stem-type valves. The air inlet valve is in a normally open position and the safety valve is in a normally closed position. As the pressure increases sufficiently, the safety valve opens and the air inlet valve closes.
Melrose et al, U.S. Pat. No. 4,577,661 teaches a high speed--high flow spool valve. A fast-acting high flow valve has a slotted spool in registry with a slotted sleeve providing full opening with a short valve throw. The slots in the spool and the slots in the sleeve form a mating grill-like structure. The high flow valve is operated by a linear or rotary actuator such as an electric solenoid.
Mayer et al, U.S. Pat. No. 4,300,595 teaches a solenoid control valve having a movable valve plate and a stationary valve seat situated within a passage to control the flow of fluid through the passage. The valve plate has a plurality of passages adapted to mate with a corresponding surface of the valve seat which closes the flow of fluid through the valve seat.
Bryant, U.S. Pat. No. 3,312,241 teaches a fluid control apparatus having a stationary plate with a plurality of ports and a movable plate on each the upstream and downstream side of the valve. Both the stationary plate and both movable plates have a plurality of ports or openings. The stationary plate is interposed between the two movable plates and hydraulic power actuators displace the movable plates to either provide or close communication between the ports in the movable plates and the ports in the stationary plate.
Balz, U.S. Pat. No. 4,643,226 teaches a slide gate valve having an inner chamber which accommodates a stationary valve plate. A displaceable valve plate having an annular insert, with approximately the same inside diameter as a discharge pipeline attached to the valve housing, supports the stationary valve plate. The stationary valve plate has several slots located transversely to the displacement direction of the valve plate. The displaceable valve plate also has an equal number of slots which can be brought into alignment with the slots of the stationary valve plate and thus allow fluid to flow.